The present invention relates to the manufacture of hot rolled steel strip or skelp under utilization of a continuously cast billet or ingot whereby the steel or strip making is to follow immediately the continuous casting operation.
The conventional method for making hot rolled steel strip or skelp uses a continuously cast slab ingot which is made available in some fashion and after heating to rolling temperature the ingot is rolled in several passes under utilization of several rolling stands. Typically, rolling is carried out in two stages which could be termed prerolling stage and finishing rolling stage, respectively. Therefore, this known method and procedure is not tied in with the continuous casting in a continuous or quasi-continuous operation.
The known method as described for making hot steel strip or skelp requires a considerable amount of capital expenditure. Determining factors here are the continuous casting machine and particularly the size thereof and further determining factors are the rolling stands as such. Here it has to be considered that the rolls needed for rolling down the rather thick, continuously cast ingot require strong initial stages and stands with correspondingly high consumption of energy. Also, the hall in which the equipment is placed is correspondingly quite large. casting thick ingots is indeed large and expensive, it is apparent that such a machine as an input stage for subsequent rolling is useful only if the overall throughput is indeed very large.
Recently, the demand for hot strip rolling plants has increased whereby particularly relatively small production quantities may have to be accommodated so that it is desirable to provide for an economic way of manufacturing such strip.